Electric ranges are commonly used in a large number of homes worldwide. Typically, the electric range includes a stove top having four or more coiled electrical resistance heating elements, commonly known as burners. During use, cooking vessels, such as pots, pans, kettles and the like are placed on the coiled burner element. The electrical resistance generated heat from the burner is then utilized for cooking.
During the cooking process on a standard burner of this type, a large amount of heat is lost to the surroundings. This occurs through convection and radiation losses from underneath and around the open burner element. Additionally, effective conduction of heat, the most efficient mode of transfer, occurs only in the places where actual physical contact is made between the coiled burner element and the cooking vessel. Physical contact is sometimes severely limited by unevenness of the underside of the cooking vessel. Furthermore, because there are substantial void spaces in the element, the heat conduction efficiency is reduced even more. In the areas where there is no contact, either by surface unevenness or simply due to open space between the coils, heat transmission occurs only through radiation and/or convection, both of which are inferior to conduction. The above situation is sometimes referred to as contact resistance. Practical disadvantages of contact resistance are greater use of energy through the requirements of longer cooking times and cooking at higher temperature settings to achieve the desired cooking result.
U.S. Pat. Nos. 3,569,672 and 3,845,273, both to Hurko, disclose devices including composite metal plate heating units. The upper heat transfer plate is permanently attached to the coiled burner element, and the unit is intended to totally replace the standard burner.
These heating units, while improving heat transmission qualities are thus not without their drawbacks. For example, when the burner elements burn out, the entire unit must be replaced, at great expense to the consumer. Also, since the plate that provides the upper heating or cooking surface is integral with the remainder of the unit, there is little or no flexibility. Removal for efficient cleaning of spills of food, or simply to use as a retrofit on another burner element, is not possible.
A need exists therefore for a stove top heat transfer pad to optimize the heat transfer characteristics of a stove top burner element that is removably mounted on the burner element. The pad should be simple in design, easy to install and remove for cleaning, and economical to produce.